Enantioselective Synthesis
of Chromanes by Iridium-Catalyzed Asymmetric Hydrogenation of 4<i>H</i>-Chromenes
作者:Andreas Pfaltz、Carine Valla、Alejandro Baeza、Frederik Menges
DOI:10.1055/s-0028-1087359
日期:——
Iridium complexes of chiral oxazoline-based P,N-ligands provedto be efficient catalysts for the enantioselective hydrogenationof 2-aryl- and 2-alkyl-4 H-chromenes.The best results were obtained with a ligand derived from threonine(ThrePHOX), which induced ee values of 95% to >99% inthe hydrogenation of 2-methyl-, 2-cyclohexyl- and various 2-aryl-substitutedchromenes.
手性恶唑啉基P,N-配体的铱配合物被证明是2-芳基-和2-烷基-4 H-色烯对映选择性加氢的有效催化剂。使用苏氨酸衍生的配体(ThrePHOX)获得了最好的结果。在 2-甲基-、2-环己基-和各种 2-芳基-取代的色烯的氢化中诱导 ee 值达到 95% 至 >99%。